温室辣椒生长和氮素吸收对增氧滴灌的响应

Response of pepper growth and nitrogen uptake to aerated drip irrigationin greenhouse

以‘康大301’辣椒为供试作物,设置施氮量(低氮225 kg·hm^(-2)和常氮300 kg·hm^(-2))、掺气量(非曝气和循环曝气)和灌水量(低水量965 m^(3)·hm^(-2)和高水量1609 m^(3)·hm^(-2))3因素2水平随机区组试验,系统监测不同处理土壤水饱和度(Sr)、氧气扩散速率(ODR)、氧化还原电位(Eh)、温室辣椒生长生理指标(根系活力、净光合速率、产量和品质)和氮素吸收利用状况。结果表明,与对照处理相比,增氧滴灌处理土壤水饱和度平均降低3.09%,ODR和Eh分别显著提高11.28%和7.85%。在相同灌水量和施氮量水平下,增氧滴灌处理较对照处理净光合速率平均增幅12.97%、根系活力平均增强13.10%(P<0.05),产量平均增产18.18%(P<0.05),辣椒Vc含量和可溶性蛋白质含量分别平均增加了9.45%和18.78%(P<0.05),氮素吸收利用效率(UPEN)平均提高了17.84%(P<0.05)。综上,增氧滴灌可有效改善土壤通气性,促进辣椒生长和氮素吸收利用效率,其中灌水量1609 m^(3)·hm^(-2)、施氮量300 kg·hm^(-2)、循环曝气的组合方案为推荐方案。

Taking‘Kangda 301’pepper as the test crop,a randomized block experiment was conducted with three factors and two levels:nitrogen(N)application rate(225 kg·hm^(-2) and 300 kg·hm^(-2)),air void fraction(subsurface drip irrigation with conventional water and aerated water),and irrigation amount(965 m^(3)·hm^(-2) and 1609 m^(3)·hm^(-2)).Soil water filled pore space(WFPS),oxygen diffusion rate(ODR),oxidation-reduction potential(Eh),physiological indexes of pepper growth(root activity,net photosynthetic rate,yield and quality)and N uptake and utilization of different treatments were systematically monitored.Results showed that compared with the control,the soil water filled pore space treatments decreased by 3.09%,and ODR and Eh increased by 11.28%and 7.85%significantly in aerated drip irrigation.Under the same irrigation amount and N application rate,the photosynthetic rate,root activity,yield,Vc content,and soluble protein content in aerated drip irrigation treatments increased by 12.97,13.10(P<0.05),18.18(P<0.05),9.45,and 18.78%(P<0.05),respectively,and N uptake and utilization efficiency increased by 17.84%(P<0.05)compared to the control.In summary,aerated drip irrigation effectively improved soil aeration,promoted pepper growth,and enhanced N absorption capacity,and the combination of irrigation amount of 1609 m^(3)·hm^(-2),N application rate of 300 kg·hm^(-2),and air void fraction of 15%was the suggested scheme.